Rapid exchange catheter with detachable hood

ABSTRACT

A single operator exchange biliary catheter having a common distal lumen. The biliary catheter includes an elongate shaft having a proximal portion defining an ancillary lumen and a distal portion defining a common guidewire and ancillary lumen. The common distal lumen reduces the profile of the distal portion of the shaft. The elongate shaft also includes a proximal guidewire port disposed between the proximal end of the shaft and the distal end of the shaft to facilitate single operator use. A seal may be disposed adjacent the proximal guidewire port to thereby seal the port. Preferably, the shaft includes a single lumen distal portion and a bi-lumen proximal portion. The single lumen distal portion of the shaft may be curved and may include a tapered or spherically shaped distal tip.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/519,649,filed Mar. 6, 2000 now U.S. Pat. No. 6,520,951; which is acontinuation-in-part of U.S. patent application Ser. No. 09/312,340,filed on May 14, 1999, entitled “Single Operator Exchange BiliaryCatheter with Common Distal Lumen”, now U.S. Pat. No. 6,364,093; whichis a continuation-in-part application of U.S. patent application Ser.No. 09/080,520, filed on May 18, 1998, entitled “Guidewire and CatheterLocking Device and Method”, now U.S. Pat. No. 6,096,009; which is acontinuation-in-part application of U.S. patent application Ser. No.08/926,200, filed on Sep. 9, 1997, entitled “Single Operator ExchangeBiliary Catheter”, now U.S. Pat. No. 6,007,522; which claims priority toU.S. Provisional Application No. 60/025,235, filed Sep. 13, 1996,entitled “Single Operator Exchange Biliary Catheter”, the entiredisclosures of which are hereby incorporated by reference. Thisapplication is related to U.S. patent application Ser. No. 09/312,438,filed on May 14, 1999, entitled “Guidewire Insertion and Re-insertionTools and Methods of Use”, the entire disclosure of which is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to endoscopic devices andmethods of use. Specifically, the present invention relates to cathetersfor use in combination with guidewires and endoscopes.

BACKGROUND OF THE INVENTION

Endoscopic procedures for treating abnormal pathologies within thealimentary canal system and biliary tree (including the biliary,hepatic, and pancreatic ducts) are increasing in number. The endoscopeprovides access to the general area of a desired duct using directvisualization. However, the duct itself must be navigated using acatheter in conjunction with fluoroscopy and guidewires.

Catheters are known for treatment of targeted anatomical regions. Knownmethods and devices for using biliary catheters for accessing thebiliary tree for performing catheter procedures are disclosed in Weaveret al., U.S. Pat. No. 5,397,302 and Karpiel, U.S. Pat. No. 5,320,602,the disclosures of which are herein incorporated by reference. Ingeneral, for treatment of an abnormal pathology within a patient'sbiliary tree, an endoscope is first introduced into the mouth of thepatient. The endoscope includes a proximal end and a distal end, and hasa lumen extending longitudinally between the proximal and distal ends.The endoscope is guided through the patient's alimentary tract or canaluntil an opening at the distal end of the endoscope is proximate thearea to receive treatment. At this point, the endoscope allows othercomponents, such as a catheter, to access the targeted area.

For visualization or treatment within the biliary tree, the distal endof the endoscope is positioned proximate the papilla of vater leading tothe common bile duct and the pancreatic duct. A catheter is guidedthrough the lumen of the endoscope until a distal tip of the catheteremerges from the opening at the distal end of the endoscope.

The catheter may be used for accessing the biliary tree. The distal endof the catheter is guided through the orifice to the papilla of vater(located between the sphincter of oddi) leading to the common bile ductand the pancreatic duct. A guidewire may be used in conjunction with thecatheter to facilitate accessing a desired location within the biliarytree. The guidewire is inserted in an opening at a proximal end of thecatheter and guided through the catheter until it emerges from thedistal end of the catheter.

If visualization of the common bile duct is desired, the guidewire isguided into the common bile duct. The catheter is advanced over theguidewire, as previously described, until the distal end of the catheteris positioned in the common bile duct at the desired location. Thecatheter is now in position for delivery of contrast media forfluoroscopic visualization of anatomical detail within the common bileduct. Once the guidewire is in place relative to the targeted area, itis highly desirable to maintain that position of the guidewire duringsubsequent catheter procedures, including catheter exchange procedures.

Present biliary endoscopic procedures include the use of multi-lumencatheters for endoscopic retrograde cholangiopancreatography, endoscopicretrograde sphincterotomy, the use of balloon catheters having retrievalballoons, stenting, and other therapeutic and diagnostic procedures. Asdescribed in general above, these present biliary endoscopic proceduresare performed using guidewire techniques. The present devices utilizedin these procedures are at least 200 cm long since they pass through theendoscope, which is commonly at least 150 cm long. Therefore, when usinga standard catheter having a guidewire lumen extending the full lengthof the catheter, guidewires used during these procedures must be atleast 450 cm in length to accommodate the exchanging of differentdevices while maintaining access and position within the biliary tree.The exchange of devices over a 450 cm guidewire is both time consumingand cumbersome.

Due to the length of the guidewire, physicians require at least twoassistants in the room to perform the biliary endoscopic procedure.Typically, one assistant is responsible for the patient anddevice-related concerns, while the other assistant is responsible forthe guidewire. The additional hands required due to the length of theguidewire results in a relatively more time consuming and costlyprocedure.

It is desirable to have an exchange catheter suitable for use within thealimentary canal for accessing targeted anatomical regions, such as thebiliary tree, having features which facilitate rapid exchange and allowan exchange procedure to be performed by a single operator. It isdesirable to have a biliary exchange catheter which may be used inconnection with a shorter guidewire, and requires less personnel forperforming biliary procedures. It is desirable to have a biliaryexchange catheter which limits the amount of guidewire over which thecatheter must travel.

It is also desirable to have a biliary rapid exchange catheter which maybe convertible for use between conventional guidewire techniques andrapid exchange guidewire techniques. It is desirable to have a biliaryrapid exchange catheter which is easily removable from the guidewire,and adaptable for use with most catheter systems used within thealimentary canal. It would also be desirable to have an exchangecatheter with a low profile distal portion available in a number ofdifferent sizes and shapes to accommodate variations in anatomy andprovide access to treatment sites that would otherwise be difficult toreach.

SUMMARY OF THE INVENTION

The present invention provides a single operator exchange biliarycatheter having a common distal lumen thereby reducing the profile ofthe distal portion of the shaft. In an exemplary embodiment, the presentinvention provides a biliary catheter including an elongate shaft havinga proximal portion defining an ancillary lumen and a distal portiondefining a common guidewire and ancillary lumen. The elongate shaftincludes a proximal guidewire port disposed between the proximal end ofthe shaft and the distal guidewire port to facilitate single operatoruse.

A seal may be disposed adjacent proximate the guidewire port to therebyseal the port. Preferably, the seal provides a fluid seal with orwithout the guidewire disposed therein. The seal may be a wide varietyof different types, including, but not limited to, a one-way valve typeseal.

Preferably, the shaft includes a single lumen distal portion and abi-lumen proximal portion. The single lumen distal portion of the shaftmay include a tapered or spherically shaped distal tip. The bi-lumenproximal portion may include a longitudinal channel providing access tothe proximal guidewire lumen.

In preferred embodiments, a hood may be disposed between the proximalbi-lumen portion and the distal single lumen portion to assist theguidewire in entering the guidewire lumen. Also, a constraint tube maybe disposed adjacent the proximal guidewire port to assist the guidewireinto the proximal guidewire port.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a single operator exchange catheter inaccordance with the present invention;

FIG. 1A is a cross-sectional view of the catheter of FIG. 1 taken alongthe line A—A;

FIG. 1B is a cross-sectional view of the catheter with guidewire of FIG.1 taken along the line B—B;

FIG. 1C is an enlarged fragmentary perspective view of the catheter ofFIG. 1 at circle C;

FIGS. 1D and 1E are cross-sectional views of the fragment illustrated inFIG. 1C;

FIGS. 2A–2D are cross-sectional views of the catheter of FIG. 1 locatedwithin increasingly larger endoscope channels;

FIG. 3 is a perspective view of an endoscope exchange sheath assembly,without a slit, suitable for receiving the catheter of FIG. 1;

FIG. 3A is an enlarged fragmentary perspective view of the encircledsheath section of FIG. 3 at 3A;

FIG. 4 is a perspective view of an alternative embodiment sheathassembly having a slit sheath and two-piece hub, shown in an unlockedposition;

FIG. 4A is a perspective view of the two-piece hub of FIG. 4 in a lockedposition;

FIG. 4B is an enlarged fragmentary perspective view of the encircledsheath section of FIG. 4 at 4B, having a slit;

FIG. 4C is an enlarged fragmentary perspective view of a sheath section,having an overlap, an alternate embodiment of the sheath in FIG. 4B;

FIG. 5 is a perspective view of the catheter of FIG. 1 inserted throughthe endoscope sheath assembly of FIG. 4;

FIG. 6 is a perspective view of an endoscope sheath section containing acatheter having a U-shaped channel containing a guidewire;

FIG. 7 is a partial perspective view of a guidewire within the catheterof FIG. 1 inserted through the endoscope sheath assembly of FIG. 4,which is in turn within an endoscope;

FIG. 7A is a perspective view of the sheath assembly of FIG. 7, havingthe catheter removed;

FIG. 8 is a partial perspective view of an alternative embodiment of asheath assembly, including an introducer;

FIG. 8A is an enlarged perspective view of the introducer of FIG. 8;

FIG. 9A is an enlarged, cross-sectional view of an alternativeembodiment of the introducer of FIG. 8;

FIG. 9B is an enlarged, cross-sectional view of another alternativeembodiment of the introducer of FIG. 8;

FIG. 9C is an enlarged, cross-sectional view of another alternativeembodiment of the introducer of FIG. 8;

FIG. 9D is an enlarged, cross-sectional view of another alternativeembodiment of the introducer of FIG. 8;

FIG. 9E is an enlarged, perspective view of another alternativeembodiment of the introducer of FIG. 8;

FIG. 9F is an enlarged, cross-sectional view of another alternativeembodiment of the introducer of FIG. 8;

FIG. 10 is a perspective view of an illustrative locking device;

FIG. 11 is a partial side view of an illustrative locking devicepositioned on an endoscope having an angled side port;

FIG. 12 is a partial side view detailing the illustrative locking deviceof FIG. 11;

FIG. 13 is a perspective view of another illustrative locking device;

FIG. 14 is a perspective view of yet another illustrative lockingdevice;

FIG. 15 is a partial side view of another illustrative locking devicepositioned on an endoscope having an angled side port;

FIG. 16 is a side view of a single operator exchange catheter inaccordance with another embodiment of the present invention;

FIG. 17 is a cross-sectional view taken along line 17—17 in FIG. 16;

FIG. 18 is a cross-sectional view taken along line 18—18 in FIG. 16;

FIG. 19A is a detailed side view of a first embodiment of section 19 inFIG. 16;

FIGS. 20A–22A are cross-sectional views taken along lines 20A—20A,21A—21A and 22A—22A, respectively, in FIG. 19A;

FIG. 19B is a detailed side view of a second embodiment of section 19 inFIG. 16;

FIGS. 20B–22B are cross-sectional views taken along lines 20B—20B,21B—21B and 22B—22B, respectively, in FIG. 19B;

FIG. 19C is a detailed side view of a third embodiment of section 19 inFIG. 16;

FIGS. 20C–22C are cross-sectional views taken along lines 20C—20C,21C—21C and 22C—22C, respectively, in FIG. 19C;

FIGS. 23A—23C are detailed side views of several embodiments of section23 in FIG. 16;

FIGS. 24A—24C are cross-sectional views taken along lines 24A—24A,24B—24B, and 24C—24C in FIGS. 23A—23C, respectively;

FIG. 25 is a plan view of a single operator exchange catheter inaccordance with another embodiment of the present invention;

FIG. 26 is a detailed plan view of an entry region of one embodiment ofthe single operator exchange catheter of FIG. 25;

FIG. 27 is a partial perspective view of the catheter of FIG. 25detailing a detachable hood;

FIG. 28 is a detailed cross-sectional view of an entry region of oneembodiment of the single operator exchange catheter of FIG. 25;

FIG. 29 is a detailed cross-sectional view of an entry region of oneembodiment of the single operator exchange catheter of FIG. 25 disposedwithin a lumen of a device;

FIG. 30 is a detailed cross-sectional view of an entry region of oneembodiment of the single operator exchange catheter of FIG. 25 disposedwithin a lumen of a device;

FIG. 31 is a detailed plan view of an entry region of one embodiment ofthe single operator exchange catheter of FIG. 25; and

FIG. 32 is a detailed cross-sectional view of an entry region of oneembodiment of the single operator exchange catheter of FIG. 25.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictselected preferred embodiments and are not intended to limit the scopeor spirit of the invention.

FIG. 1 shows a perspective view of a catheter assembly 30 in accordancewith the present invention. Catheter assembly 30 is used in catheterprocedures for accessing targeted anatomical regions through thealimentary canal. The present invention incorporates features whichallow rapid exchange of a catheter by a single operator. The catheter ofthe present invention allows shorter length guidewires to be used,resulting in procedures which require less medical personnel, are lesstime consuming, and less costly. Additionally, the present invention isadaptable to most catheter devices used for catheter procedures withinthe alimentary canal.

Catheter assembly 30 includes a catheter hub assembly 32 and a catheter34, having a guidewire 36 passing through a portion thereof. Catheter 34includes a shaft 38, which in general terms has a proximal end 40, aU-channel 42, a distal tip region 44, a distal end 46 and various lumensdescribed in greater detail below. Catheter hub assembly 32 is operablyconnected to proximal end 40 of shaft 38. Catheter hub assembly 32 ispreferably configured to couple to ancillary devices allowing access toa lumen within shaft 38.

Shaft 38 is a generally tubular shaped member having a generally uniformouter shape at proximal end 40. Shaft 38 may be sized for slidablepassage through the lumen of an endoscope (not shown). Shaft 38 ispreferably formed in an extrusion process. Shaft 38 may be formed of anextruded polymeric material. In one embodiment, the preferred polymericmaterial is polytetrafluoroethylene, polyether block amide, nylon or acombination or blend of these. Catheters which are contemplated include,but are not limited to, cannulas, sphincterotomes, cytology devices, anddevices for stone retrieval and stent placement.

In a preferred embodiment, shaft 38 further includes a distal taper 48which tapers to distal tip region 44. Additionally, tip region 44 mayinclude high contrast, color coded distal markers 50. Finally, distalend 46 may be radiopaque for fluoroscopic visualization of distal tipregion 44 during a catheter procedure.

U-channel 42 of shaft 38 extends between a first, proximal channel end52 and a second, distal channel end 54. U-channel 42 serves to contain,but not necessarily constrain, guidewire 36, between channel proximalend 52 and channel distal end 54. The term “U-channel” refers to achannel shape that allows radial removal of guidewire 36 from thechannel 42, and need not be strictly in the shape of the letter U.Channel 42 in the preferred embodiment is sufficiently large to allowunhindered radial guidewire 36 movement out of channel 42. Further, thechannel walls and radial opening are substantially equal to or slightlylarger than the diameter of a guidewire lumen, described in greaterdetail below. Although it is recognized that proximal channel end 52 maybe located at any location distal of proximal end 40 of shaft 38,channel distal end 54 is preferably located between 10 and 40 cm fromdistal end 46 of catheter shaft 38.

Finally, as shown in FIG. 1A, which is a cross-sectional view of shaft38 taken along line A—A at a location proximal of channel proximal end52, shaft 38 includes ancillary lumen 56, ancillary lumen 58 andguidewire lumen 60.

Ancillary lumen 56 and ancillary lumen 58 extend longitudinally betweenproximal end 40 and distal end 46 of shaft 38. Ancillary lumen 56 andancillary lumen 58 may be injection lumens, allowing for high contrastmedia flow capability for bubble-free opacification and for excellentvisualization of a desired anatomical region. Additionally oralternatively, ancillary lumen 56 and/or ancillary lumen 58 may be usedfor or as part of other ancillary devices, such as a cutting wire lumenor a retrieval balloon lumen.

Guidewire lumen 60 extends longitudinally between proximal end 40 anddistal end 46 of shaft 38 in the preferred embodiment. Further,guidewire lumen 60 is sized to receive guidewire 36. Guidewire lumen 60may be a tubular member which is extruded integral catheter shaft 38, oralternatively, guidewire lumen 60 may be a separate tubular member whichis coupled to catheter shaft 38. Although in one preferred embodimentthe guidewire lumen 60 is a tubular member which is located proximatedistal end 46 of catheter shaft 38, it is recognized that guidewirelumen 60 may be formed anywhere along shaft 38, may be an extension ofshaft 38 coupled to distal end 46, or guidewire lumen 60 may run theentire length of shaft 38.

Referring to FIG. 1B, a cross-sectional view of shaft 38 taken alongline B—B of FIG. 1 is shown. Guidewire 36 may access guidewire lumen 60at a point proximal channel distal end 54. Guidewire 36 extends withinchannel 42 to channel distal end 54, continuing within guidewire lumen60 through distal tip region 44, and exiting through an opening indistal end 46.

Referring to FIG. 1C, a section of catheter shaft 38 having U-channel 42is shown. The embodiment shown also includes ancillary lumens 56 and 58.Sections of shaft 38 proximate the channel proximal end 52 and distalchannel distal end 54 contain guidewire lumen 60 in communication withU-channel 42. In one embodiment, U-channel 42 has an interior,closed-side geometry, substantially the same as the geometry ofguidewire lumen 60. Further, U-channel 42 walls are spaced further thana diameter of guidewire 36 such that guidewire 36 moves freely into andout of U-channel 42.

Catheter shaft 38 can be configured such that U-channel 42 is definedseparately from guidewire lumen 60. With this approach, guidewire lumen60 is divided into two sections; a first section extending betweenproximal end 40 of shaft 38 and channel proximal end 52; and a secondportion extending between channel distal end 54 and distal end 46 ofshaft 38. Alternatively, the shaft can be configured to define guidewirelumen 60 as extending longitudinally between proximal end 40 and distalend 46 of shaft 38. In the alternative embodiment, between channelproximal end 52 and channel distal end 54, guidewire lumen 60 isintegral with U-channel 42. In other words, guidewire lumen 60 defines aportion of U-channel 42 such that spacing between outer walls ofU-channel 42 is equal to a diameter of guidewire lumen 60. Regardless ofhow guidewire lumen 60 and U-channel 42 are defined, U-channel 42provides for access to guidewire lumen 60 at channel distal end 54. Inthis regard, channel distal end 54 can be enlarged to more easily directguidewire 36 into guidewire lumen 60.

Guidewire lumen 60 and U-channel 42 allow rapid exchange of catheterassembly 30 when an alternative catheter is necessary during a certainmedical procedure. Shorter length guidewires may be used since guidewire36 does not pass through shaft proximal end 40 and hub assembly 32, butrather exits the catheter shaft 38 at U-channel 42 located substantiallydistal from proximal end 40. The unique catheter construction inaccordance with the present invention will reduce catheter therapeuticand diagnostic procedure time since catheter device exchanges may beperformed relatively more easily and quickly by a single operator.Additional personnel and time associated with maintaining the placementof a conventional (approximately 400 cm) guidewire within the targetedanatomical region is eliminated, reducing the overall costs of theprocedure.

Referring now to FIGS. 1D and 1E, which are cross-sectional views of theshaft 38 fragment illustrated in FIG. 1C. Specifically, FIG. 1D is aprecise cross-sectional view of the shaft 38 fragment illustrated inFIG. 1C, and FIG. 1E is an alternative cross-sectional view of the shaft38 fragment illustrated in FIG. 1C. As described previously and now withreference to FIG. 1D, catheter shaft 38 includes a U-channel 42, a firstancillary lumen 56 and a second ancillary lumen 58. In this embodiment,U-channel 42 collectively defines a guidewire lumen and an openingproviding access to the guidewire lumen. Similarly, in the embodimentillustrated in FIG. 1E, C-channel 43 collectively defines a guidewirelumen and a narrower opening for accessing the guidewire lumen. Thenarrower opening of C-channel 43 may have a dimension of approximately0.018 inches and is designed to better contain the guidewire therein.C-channel 43 may eliminate the need for a separate exchange sheath whenusing endoscopes with larger lumens.

Referring to FIGS. 2A through 2D, cross-sectional views of endoscopeworking channels 70–76 containing a catheter according to FIG. 1 areshown. In the examples illustrated in FIGS. 2A through 2D, workingchannel inside diameters 70, 72, 74, and 76 are 2.8, 3.2, 3.8, and 4.2mm; respectively. FIG. 2A illustrates catheter shaft 38 having ancillarylumens 56 and 58, U-channel 42, and guidewire 36 within U-channel 42.Further, shaft 38 is shown within a first size endoscope working channel70. In FIG. 2A, guidewire 36 is effectively radially constrained bysmall sized working channel 70 that closely surrounds U-channel 42.

FIG. 2B illustrates catheter containment within a second size workingchannel 72, slightly larger than the working channel 70 of FIG. 2A. InFIG. 2B, guidewire 36 is able to move out of U-channel 42 to a positiondenoted with dashed lines at 80. FIG. 2C shows shaft 38 contained withina third, even larger sized working channel 74. Guidewire 36 is able tomove completely out of U-channel 42 to position 82 shown with dashedlines. Finally, FIG. 2D demonstrates catheter shaft 38 within a fourthsize working channel 76. In this even larger working channel, guidewire36 lies within an even larger cross-sectional area, and is able to moveto a position shown in FIG. 2D with dashed lines at 84.

As shown with the larger endoscope working channels (FIGS. 2C and 2D),the potential for guidewire 36 to slip out of U-channel 42 creates apotential for the guidewire 36 to become pinched and restrict desiredmovements of both guidewire 36 and catheter shaft 38. For this reason,when larger endoscope working channels are used, an exchange sheathhaving a sufficiently small inner diameter so as to constrain guidewiremovement to within the catheter U-channel 42 is employed with onepreferred embodiment. Generally speaking, an endoscope exchange sheathin accordance with one preferred embodiment allows for use of a radiallyaccessible guidewire, which is longitudinally aligned with the catheter,while presenting a circular profile to an endoscope and mitigatingguidewire pinching problems between the catheter and the endoscopeworking channel wall.

Referring to FIG. 3, an endoscope exchange sheath assembly 100 havingsheath hub assembly 102 and a sheath 104 is shown. The sheath 104includes a lumen 106 and a distal end 108. FIG. 3A shows a section ofsheath 104, having lumen 106 for receiving a catheter. Basically, withreference to FIG. 1, catheter 34 is fed through lumen 106 of sheath 104such that sheath 104 encompasses guidewire 36 within U-channel 42.Sheath 104 is adapted to be disposed within an endoscope workingchannel, thereby providing a smaller diameter channel than that of thesurrounding endoscope working channel constraining the guidewire 34(FIG. 1) to the U-channel 50 (FIG. 1), and mitigating the potentialproblems shown in FIGS. 2C and 2D.

Referring to FIG. 4, an alternate endoscope exchange sheath assembly 110is shown. Sheath assembly 110 includes a two-piece hub assembly 112 anda sheath 114 defining lumen 116 and having slit 118 extendinglongitudinally over its length, terminating at distal end 120. Slit 118in sheath 114 is shown in more detail in FIG. 4B.

Referring again to FIG. 4, two-piece hub assembly 112 has a proximal hubportion 122 and a distal hub portion 124, having a proximal slit 126 anda distal slit 128, respectively. Sheath slit 118 is in communicationwith hub slits 126 and 128, allowing a guidewire (not shown) to beradially slid into or out of sheath assembly 110. Proximal hub portion122 is shown unlocked (position “A”) in FIG. 4, aligning hub proximalslit 126 with hub distal slit 128 and sheath slit 118, providing acontinuous slit for guidewire radial movement into and out of the sheathassembly 110. Proximal hub portion 122 is shown locked, in position “B”,in FIG. 4A, whereby proximal hub slit 126 is rotated with respect todistal hub slit 128, preventing a guidewire (not shown) within hubassembly 112 from being moved radially out of hub assembly 112. Proximalhub portion 122 is set to position B (FIG. 4A) when radial guidewiremovement is not desired.

FIG. 4C illustrates a portion of an alternate embodiment sheath 130having a lumen 132, a sheath wall opening 134 and sheath wall overlap136. A guidewire (not shown) is able to be slid out of lumen 132 ofsheath 130 by maneuvering the guidewire into sheath wall opening 134 andthrough overlap 136.

Referring to FIG. 5, catheter assembly 30 depicted in FIG. 1 is showninserted within endoscope exchange sheath assembly 110 depicted in FIG.4. More particularly, catheter 34 is inserted through slitted sheathassembly 110, extending distally out sheath distal end 120. Guidewire 36(shown partially in FIG. 5) is positioned within U-channel 42 ofcatheter 34, along guidewire lumen 60 (FIG. 1B), and extends from shaftdistal end 46. Further, guidewire 36 is engaged by hub assembly 112.More particularly, guidewire 36 passes within and is engaged by proximalslit 126 and distal slit 128 of hub assembly 112. Sheath proximal hubportion 122, having proximal slit 126, is shown in locked positionrelative to sheath distal hub portion 124, having distal slit 128. Thus,in the locked position, hub assembly 112 of sheath assembly 110 preventsradial withdrawal of guidewire 36, otherwise inserted in U-channel 42 ofcatheter 34, from distal the channel proximal end 52.

Referring to FIG. 6, a section of FIG. 5 is shown in detail, havingendoscope sheath 114 containing catheter shaft 38, which furthermaintains guidewire 36 within U-channel 42. As shown, sheath 114 is ableto constrain movement of guidewire 36 from U-channel 42 when sheath 114is within a larger endoscope working channel, for example as illustratedin FIGS. 2C and 2D. Importantly, the sheath 114 embodiment illustratedin FIG. 6 includes longitudinal slit 118, allowing guidewire 36 to bepeeled from catheter shaft 38 and endoscope sheath 114. In other words,as previously described, U-channel 42 is sized larger than guidewire 36such that guidewire 36 can displace radially from U-channel 42. Sheath114 prevents undesired displacement of guidewire 36 from U-channel 42under normal operating conditions. However, if adequate radial force isplaced on guidewire 36 by an operator, guidewire 36 will separate sheath114 along slit 118 such that guidewire 36 is displaced from sheath 114and U-channel 42.

Referring to FIG. 7, guidewire 36 is shown inserted within catheterassembly 30 of FIG. 1, which is inserted through endoscope sheathassembly 110 of FIG. 4, which is in turn within an endoscope 150. Sheathassembly 110 includes sheath 114 that has slit 118 and two-piece hubassembly 112, shown at a locked position “B” (also in FIG. 4A). Havinghub assembly 112 locked prevents guidewire 36 from moving radially outof sheath 114 through slit 118. Guidewire 36 can be restrained fromlongitudinal movement by applying finger pressure on the guidewire 36against hub assembly 112.

Referring to FIG. 7A, endoscope 150 and sheath assembly 110 of FIG. 7are shown without the catheter assembly 30 inserted, as after catheterwithdrawal. Sheath hub assembly 112 is shown in unlocked position at “A”(also in FIG. 4). Having hub assembly 112 unlocked allows radialmovement of guidewire 36 out of sheath 114 through slit 118, but suchmovement may be restrained by trapping guidewire 36 against the outsideof sheath 114 using one finger, providing ease of guidewire 36 controlduring catheter exchanges.

In one possible endoscopic procedure, an endoscope 150, as illustratedin FIG. 7, is first introduced into the mouth of a patient and is guidedthrough the patient's alimentary canal. Specifically, endoscope 150 isguided down the esophagus, through the stomach, past the pyloricsphincter of the stomach and into the duodenum. Endoscope 150 has alumen extending longitudinally between its proximal end and the distalend.

Endoscope 150 is guided through the alimentary canal until a distal end(not shown) of endoscope 150 is proximate the target area within theanatomy to receive treatment. In an endoscopic biliary procedure,endoscope 150 is guided into the duodenum until the opening at thedistal end of the endoscope 150 is proximate the papilla of vater. Thepapilla of vater is located between the sphincter of oddi, which leadsto the common bile duct, hepatic, and pancreatic ducts. The proximal end(shown in FIGS. 7 and 7A) of endoscope 150 extends and remains outsidethe mouth of the patient.

With endoscope 150 properly positioned within the patient, catheterassembly 30 is prepared for insertion into the endoscope. First,guidewire 36 is fed into the guidewire lumen 60 (FIGS. 1A–1C) of shaft38. More particularly, a distal end of guidewire 36 is placed withinU-channel 42, distal the channel proximal end 52. The guidewire 36 isthen fed to channel distal end 54 (FIG. 1) into guidewire lumen 60.Finally, guidewire 36 is fed through shaft 38 to distal tip region 40(FIG. 1). In one method, catheter 32 is then inserted directly intoendoscope 150 working channel. This method may be practiced with anendoscope having a sufficiently small working channel inside diameter,as illustrated in FIG. 2A, to constrain guidewire 36 movement without asheath.

However, in a preferred method (with reference to FIG. 7), catheterassembly 30, threaded with guidewire 36, is inserted into sheathassembly 110, thereby constraining guidewire 36 from slipping radiallyout of U-channel 42. More particularly, catheter 34 is inserted intoendoscope 150 working channel, but leaving channel proximal end 52proximate sheath hub assembly 112, and leaving a portion of guidewire 36extending from the channel proximal end 52 as well. Notably, sheath hubassembly 112 includes hub slits 126 and 128 which receive a portion ofguidewire 36. Thus, in the preferred embodiment, hub assembly 112 islocked, preventing unwanted radial guidewire 36 movement. In a preferredmethod, the loading of guidewire 34 into catheter shaft 38 and cathetershaft 38 into sheath assembly 110 is done prior to inserting endoscope150 into a patient (not shown).

Endoscope sheath 114, containing catheter shaft 38, is inserted intoendoscope 150 working channel. Endoscope sheath 114 serves to constrainradial guidewire 36 movement over the approximate length of U-channel42. Catheter shaft 38 and sheath 114 are inserted together intoendoscope 150 until both are near a distal end (not shown) of endoscope150. Catheter shaft 38 and sheath 114 may be, either or both, advanceduntil exiting the distal end of endoscope 150.

In one method, guidewire 36 is advanced until guidewire 36 distal tip ispositioned within the target area in the biliary tree (including thecommon bile, hepatic or pancreatic ducts). For example, the distal tipof guidewire 36 may be guided through the orifice leading to the papillaof vater for access to the biliary tree. Catheter shaft 38 may then beadvanced over guidewire 36, tracking catheter assembly 30, untilcatheter distal tip region 40 (FIG. 1) exits distal end of endoscope 150and is positioned within the desired duct. In another method, guidewire36 and catheter assembly 30 are advanced together until catheter distalend 42 (FIG. 1) is positioned at the target area. It is also recognizedthat the catheter could be first advanced to near the target area,followed by inserting the guidewire when needed to advance the catheterfurther.

Once guidewire 36 is in position at the target area, catheterprocedures, including injecting contrast media, such as radiopaque dye,through ancillary lumens 56 or 58 (FIGS. 1A–1C) into the common bileduct for visualization of the duct, can be performed. After the desiredcatheter procedure has been completed, catheter assembly 30 can beexchanged or removed from endoscope 150, leaving guidewire 36 inposition for other catheter procedures. Catheter assembly 30 and sheathassembly 110 may also be removed together.

One method of withdrawing catheter 34 from endoscope 150 is possibleusing either a slitted/overlapped endoscope sheath 114 as depicted inFIGS. 4 through 4C, or a sheath 104 without a slit as depicted in FIGS.3 through 3A. Using this method, best visualized with reference to FIG.7, guidewire 36 is held to prevent longitudinal movement while catheter34 is retracted within endoscope sheath 114 (or 104). Catheter 34retraction leaving the guidewire 36 in position within the patient isenabled by U-channel 42 being radially open to guidewire 36 removal incatheter shaft 36. Once catheter retraction has brought channel distalend 54 (FIG. 1) to a point proximate sheath hub assembly 112, only arelatively short portion of guidewire 36, from channel distal end 54 todistal end 46 (FIG. 1) of catheter shaft 38, remains within catheter 34.A single operator can remove this remaining portion of guidewire 36 fromcatheter 34 by first slightly retracting catheter assembly 30 (whilestill holding guidewire 34 in place) out of sheath assembly 110 (or100), such that a portion of guidewire 36 is accessible distal ofcatheter distal end 46. In other words, a small portion of guidewire 36is accessible between distal end 46 of catheter 34 and distal hubportion 124 of sheath assembly 110. The accessible portion of guidewire36 is then held by the operator, while withdrawing the remaining portionof catheter 34 completely over guidewire 36. In an alternative method,the distal end of the endoscope can include an elevator which could beutilized to lock the distal end of the guidewire in position while thecatheter is removed.

Exchange of endoscope sheath assembly 110 may be desired, as when astent (not shown) is to be advanced over guidewire 36, and the stent hasa larger outside diameter than can be accommodated by the sheath 114.One method of exchanging an endoscope sheath assembly 110 may be usedwhere sheath 114 is slitted as in FIG. 4B, or overlapped, as in sheath130 in FIG. 4C. Referring to FIG. 7A, two-piece hub assembly 112 isturned to the unlocked position “A” (also shown in FIG. 4). Guidewire 36is pulled radially away from sheath hub assembly 112 and through slit118 in sheath 114. Guidewire 36 is then held, preferably against someportion of endoscope 150, to prevent guidewire 36 from being dislodgedfrom position within the patient. Sheath 114 is retracted from endoscope150, guidewire 36 being “peeled” away from sheath 114. Sheath retractionis continued until sheath 114 is completely outside of endoscope 150 andover guidewire 36. At this point, guidewire 36 is within endoscope 150working channel, and stents, catheters, and endoscope sheaths may beadvanced over guidewire 36.

Another method of exchanging both endoscope sheath assembly 110 andcatheter assembly 30 may be used where the sheath 114 is slitted as inFIG. 4B, or overlapped, as in sheath 130 in FIG. 4C. Referring to FIGS.7 and 7A, two-piece hub assembly 112 is turned to the unlocked position“A” (FIG. 7A). Guidewire 36 is pulled radially away from U-channel 42 ofcatheter 34, from hub assembly 112 and through slit 118 in sheath 114.Guidewire 36 is then held, preferably against some portion of endoscope150, to prevent guidewire 36 from being dislodged from position withinthe patient. Sheath 114 and catheter 34 are retracted from endoscope150, with guidewire 36 being “peeled” away from sheath 114. Sheathassembly 110 and catheter assembly 30 retraction are continued untilsheath 114 and catheter 34 are completely outside of endoscope 150 andover guidewire 36. At this point, guidewire 36 remains in a positionwithin endoscope 150 and patient. A single operator can access a smallportion of guidewire 36 between distal end 46 (FIG. 1) of catheter 34 tohold guidewire 36 in place while catheter assembly 30 is completelyremoved or disengaged from guidewire 36.

While sheath assembly 110 has been described as including a two-piecehub assembly 112 in conjunction with sheath 114, other assemblies may beused. For example, referring to FIG. 8, an alternate sheath assembly 160is shown. Sheath assembly 160 includes an introducer 162, an attachmentmeans 164 and a sheath 166. Similar to previous embodiments, sheath 166defines a lumen (not shown) and includes a slit 168 extendinglongitudinally over its length, terminating at a distal end 170. Sheath166 is generally identical to sheath 104 and sheath 114 previouslydescribed. Introducer 162 is attached to sheath 166 by attachment means164 such that lumen (not shown) of sheath 166 is in fluid communicationwith an interior portion of introducer 162. In one preferred embodiment,attachment means 164 is a flexible membrane which seals sheath 166 tointroducer 162. Alternatively, other forms of attachment, such as anadhesive or frictional engagement between introducer 162 and sheath 166may also be useful.

Referring to FIG. 8A, introducer 162 is shown in greater detail.Introducer 162 is a funnel-shaped device including a horn 172 and a neck174. In one preferred embodiment, horn 172 and neck 174 are integrallyformed as a singular body.

Horn 172 is preferably a conically-shaped body having an outer wall 176.Outer wall 176 defines an interior space and includes aguidewire-receiving notch 180 formed near proximal end 182 of horn 172.Guidewire-receiving notch 180 is preferably J-shaped and includes anentry end 184 and a locking end 186. As shown in FIG. 8A, entry end 184is open at proximal end 182 of horn 172. Conversely, locking end 186 isclosed.

Neck 174 is preferably tubular in shape, and includes a passage 188.Passage 188 is configured to be in fluid communication with interiorspace of horn 172. In the preferred embodiment, horn 172 and neck 174are formed of a plastic material. Alternatively, any other semi-rigid orrigid, surgically-safe material may be used.

Referring to FIGS. 1, 8 and 8A, during use, catheter assembly 34(FIG. 1) is inserted within sheath assembly 160. More particularly,distal end 46 (FIG. 1) of catheter shaft 38 (FIG. 1), includingguidewire 36 (FIG. 1) is placed within horn 172 of introducer 162. Theconical shape of horn 172 assists in directing distal end 46 of cathetershaft 38, including guidewire 36, into passage 188 of neck 174. Cathetershaft 38 continues forward within lumen (not shown) of sheath 166 untildistal end 46 of catheter shaft 38 extends from distal end 170 of sheath166.

Once properly inserted within sheath assembly 160, a proximal end ofguidewire 36 (FIG. 1) is maintained within guidewire-receiving notch180. More particularly, a portion of guidewire 36 is forced by anoperator through entry end 184 of guidewire-receiving notch 180 andforced within locking end 186 thereof. In this regard, locking end 186preferably has a diameter slightly smaller than that of guidewire 36.Thus, locking end 186 frictionally maintains guidewire 36. Conversely,guidewire 36 can easily be released from guidewire-receiving notch 180by sliding guidewire 36 from locking end 186 and out of entry end 184.Thus, sheath assembly 160 functions in a manner highly similar to sheathassembly 100 and sheath assembly 110 previously described.

Referring to FIG. 9A, an alternative embodiment of an introducer 190 isshown. Introducer 190 includes a horn 192, a neck 194 and a valve 196.Similar to previous embodiment, horn 192 and neck 194 are preferablyintegrally formed as a singular body. Horn 192 includes an outer wall197 which defines a guidewire-receiving notch 198 and valve-receivingslots 200. Valve 196 includes a valve body 202 sized to fit within outerwall 197 of horn 192. Further, valve 196 includes ribs 204 extendingfrom valve body 202. Ribs 204 are preferably sized to mate withinvalve-receiving slots 200 of horn 192. Thus, valve 196 is maintainedwithin horn 192 via interaction of ribs 204 with valve-receiving slots200. In this regard, valve-receiving slots 200 are preferably positionedalong horn 192 proximal neck 194. Valve 196 is preferably made of arubber-type material.

During use, introducer 190 functions in a manner highly similar tointroducer 162 (FIGS. 8 and 8A) previously described. Additionally,however, valve 196 forms a seal about catheter shaft 38 (FIG. 1). Thus,upon insertion into a human body, valve 196 prevents bodily fluids, suchas bile, from backing up through the sheath assembly. Additionally,valve 196 can provide for aspiration, if desired.

Referring to FIG. 9B, an alternative embodiment of an introducer 206 isshown. Introducer 206 is highly similar to introducer 190 (FIG. 9A)previously described. In this regard, introducer 206 includes a horn208, a neck 210 and a valve 212. Horn 208 is preferably integrallyformed with neck 210 and includes an outer wall 214 defining aguidewire-receiving notch 216 and valve-receiving slots 218. Similar tovalve 196 (FIG. 9A), valve 212 includes a valve body 220 and ribs 222.Ribs 222 are sized to mate within valve-receiving slots 218 of horn 208.In this regard, valve-receiving slots 218 are positioned proximate aproximal end 224 of horn 208. Introducer 206, including valve 212,functions in a manner highly similar to introducer 190 (FIG. 9A) aspreviously described.

It is recognized that the fluid blocking function provided by valve 212can be achieved with other designs. For example, referring to FIG. 9C,an alternative embodiment of an introducer 226 is shown. Introducer 226includes a horn 228, a neck 230 and an O-ring 232. Horn 228 and neck 230are preferably formed as an integral body. Horn 228 preferably includesa guidewire-receiving notch (not shown) similar to that previouslydescribed and an interior slot 234. Interior slot 234 is preferablypositioned proximate neck 230 and is sized to maintain O-ring 232.Alternatively, interior slot 234 can be formed in neck 230.

O-ring 232 is preferably made of a rubber-type material. Further, O-ring232 has an inner diameter slightly smaller than that of horn 228 andneck 230. Thus, during use, O-ring 232 forms a seal about catheter shaft38 (FIG. 1), blocking passage of bodily fluids, such as bile, into horn228.

Referring to FIG. 9D, another alternative embodiment of an introducer236 is shown. Introducer 236 is similar to a touhey-borst system andincludes an upper horn section 238, a lower horn section 240 and agrommet 242. Upper horn section 238 includes an outer wall 244 defininga proximal end 246, a grommet-receiving flange 248 and a distal end 250.Proximal end 246 of horn section 238 preferably includes aguidewire-receiving notch (not shown) similar to that previouslydescribed. Distal end 250 is threaded and includes a passage 252 sizedto receive a portion of lower horn section 240.

Lower horn section 240 includes a body 254 defining a proximal end 256,an intermediate portion 258 and a distal end 260. An interior passage266 is configured to communicate with passage 252 and extends fromproximal end 256 to distal end 260. Finally, proximal end 256 includes athreaded slot 262 sized to threadably receive distal end 250 of upperhorn section 238.

Grommet 242 is preferably made of a rubber-type material and is sized tonest within grommet-receiving flange 248 of upper horn section 238 whileabutting proximal end 256 of lower horn section 240.

Introducer 236 is assembled by placing grommet 242 withingrommet-receiving flange 248 of upper horn section 238. Distal end 250of upper horn section 238 is then threadably secured to proximal end 258of lower horn section 240. As upper horn section 238 is threadablysecured to lower horn section 240, proximal end 256 of lower hornsection 240 compresses grommet 242 within grommet-receiving flange 248of upper horn section 238. During use, introducer 236 functions in amanner highly similar to that previously described. In this regard,grommet 242 forms a seal about catheter shaft 38 (FIG. 1). Further,aspiration can be achieved, if desired, by loosening lower horn section240 relative to upper horn section 238.

Referring to FIG. 9E, yet another alternative embodiment of anintroducer 266 is shown. Introducer 266 includes a horn 268, a neck 270and a valve 272. Preferably, horn 268, neck 270 and valve 272 areintegrally formed as a singular body. In this regard, valve 272 isformed while molding horn 268 and neck 270 by imparting a controlledflash at distal end 274 of neck 270.

Introducer 266 performs in a manner highly similar to that previouslydescribed. Thus, valve 272 forms a seal about catheter shaft 38 (FIG.1), thereby preventing back flow of bodily fluids, such as bile, intohorn 268.

Referring to FIG. 9F, another alternative embodiment of an introducer276 is shown. Introducer 276 includes a horn 278, a neck 280 and a valve282. Horn 278 and neck 280 are preferably integrally formed as asingular body. In this regard, horn 278 and neck 280 are defined by anouter wall 284. Outer wall 284 forms a guidewire-receiving notch 286 andan exterior slot 288. Guidewire-receiving notch 286 is similar to thatpreviously described. Exterior slot 288 is positioned along neck 280 andis sized to maintain a portion of valve 282. Alternatively, exteriorslot 288 can be positioned along horn 278.

Valve 282 is preferably a rubber-type sock defined by an upper rib 290,a side wall 292 and a shoulder 294. Upper rib 290 is preferably sized tomount within exterior slot 288 of neck 280. Side wall 292 is preferablyflexible so as to stretch along neck 280. Finally, shoulder 294 ispreferably configured to abut a distal end 298 of neck 280. With thisconfiguration, valve 282 is placed over distal end 298 of neck 280 suchthat shoulder 294 contacts distal end 298. Due to the preferred flexiblecharacteristic of valve 282, side wall 292 is stretched until upper rib290 nests within exterior slot 288 of neck 280.

During use, the catheter shaft 38 (FIG. 1) is placed through introducer276 such that shoulder 294 of valve 282 forms a seal about cathetershaft 38. Thus, valve 282 prevents undesired back flow of bodily fluids,such as bile.

FIG. 10 is a perspective view of an illustrative locking device for usewith an endoscope having a side instrument port. The illustrativelocking device is generally shown at 320 and includes a body member 322.At one end, the body member 322 includes one or more hook members 324for attaching the locking device to a shaft of an endoscope or the like(see FIG. 11). At the other end, the body member 322 includes a securingmechanism for securing a guidewire or catheter to the locking device.

The hook members 324 may be provided in pairs, as shown in FIG. 10, oroffset from one another, as shown in FIG. 13. In either case, the hookmembers 324 are adapted to clip and secure the locking device to theshaft of an endoscope or the like.

The securing mechanism preferably includes one or more openings providedin the body member 322. In the embodiment shown, the body member 322includes a guidewire opening 326 and a catheter opening 332. Theguidewire opening 326 is similar to the guidewire-receiving notch 180 ofFIG. 8A. The guidewire opening 326 is preferably J-shaped, andpreferably includes an entry slot 328 and a locking slot 330. Thecatheter opening 332 is boot shaped, and also preferably includes anentry slot 334 and a locking slot 336.

The entry slot 328 of the guidewire opening 326 is dimensioned to belarger than the diameter of a guidewire. The locking slot 330 of theguidewire opening 326 is dimensioned to be somewhat smaller than thediameter of a guidewire. Accordingly, a guidewire can be secured to thebody member 322 by inserting a portion of the guidewire through theentry slot 328 of the guidewire opening 326 and into the locking slot330. The locking slot 330 frictionally secures the guidewire relative tothe body member 322.

Likewise, the entry slot 334 of the catheter opening 332 is dimensionedto be larger than the diameter of a catheter. The locking slot 336 ofthe catheter opening 332 is dimensioned to be somewhat smaller than thediameter of a catheter. Accordingly, a catheter can be secured to thebody member 322 by inserting a portion of the catheter through the entryend 334 of the catheter opening 332 and into the locking slot 336. Thelocking slot 336 frictionally secures the catheter relative to the bodymember 322.

FIG. 11 is a partial side view of an illustrative locking devicepositioned on an endoscope with an angled side port extending therefrom.The endoscope is generally shown at 350, and includes a main shaft 352with a lumen extending therethrough. A side port 356 extends laterallyaway from the main shaft 352 at an angle. The side port 356 providesaccess to the lumen of the main shaft 352. Accordingly, a guidewireand/or catheter may access the lumen of the main shaft 352 via the sideport 356.

The side port 356 preferably includes a side port opening 354 which islaterally spaced from the main shaft 352 due to the angular displacementbetween the main shaft 352 and the side port 356. The side port opening354 is in fluid communication with the lumen of the main shaft 352 via aconnection tube 355. The connection tube 355 intersects a side wall ofthe main shaft 352 at an angle, as shown.

A locking device having a body member 360 is shown clipped onto the mainshaft 352 of the endoscope. The body member 360 includes a number ofhook members 358 for attaching the locking device to the main shaft 352.Two hook members are visible in FIG. 11. The hook members 358 aresimilar to the hook members 324 described above with respect to FIG. 10.

The body member 360 extends away from the hook members 358 and generallyparallel to the side port 356. In FIG. 11, the body member is obscuredby the main shaft 352 and side port 356. The body member 360 extendsupward past the side port opening 354, wherein a securing mechanism isprovided. Preferably, the securing mechanism is a J-shaped guidewireopening 362.

In use, a guidewire is advanced into the body via the endoscope. Duringthe advancement of the guidewire, the proximal end thereof may be movedto a first position 364, which is in the entry slot of the guidewireopening 362. Once the guidewire is in a desired position within thebody, the guidewire may be moved to a second position 366, which is inthe locking slot of the guidewire opening 362. The locking slot of theguidewire opening 362 frictionally secures the guidewire relative to thebody member 360.

FIG. 12 is a partial side view detailing the illustrative locking deviceof FIG. 11, with an additional oversized catheter opening shown. Theside port of the endoscope is shown at 356, and the body member of thelocking device is shown at 360. Positioned proximate the side portopening 354 is a guidewire opening 362 and an oversized catheter opening370. Like above, the guidewire opening is J-shaped and includes an entryslot and a locking slot. Thus, the guidewire may be moved to the firstposition 364, which is in the entry slot of the guidewire opening 362.Once the guidewire is in a desired position within the body, theguidewire may be moved to the second position 366, which is in thelocking slot of the guidewire opening 362. The locking slot of theguidewire opening 362 frictionally secures the guidewire relative to thebody member 360.

The oversized catheter opening 370 is sized to restrict lateral movementof the catheter 372 but not longitudinal movement of the catheter 372.Providing a guidewire opening that can secure the guidewire relative tothe body member, and an oversized catheter opening for only restrictinglateral movement of the catheter 372 may be particularly useful inperforming a catheter exchange procedure. For example, during a catheterexchange procedure, the guidewire opening may maintain the position ofthe guidewire. The oversized catheter opening 370 may separate thecatheter from the guidewire, as the catheter is withdrawn. The first andsecond catheters should be single-operator exchange type catheters toprovide access to the guidewire during the exchange.

FIG. 13 is a perspective view of another illustrative locking device.The embodiment shown in FIG. 13 is similar to the embodiment shown inFIG. 10, but the hook members are laterally offset rather than aligned.For example, hook member 380 is laterally offset from hook member 382 bya distance “D”. This configuration is another example of an attachmentmechanism for attaching the body member to a catheter shaft.

FIG. 14 is a perspective view of yet another illustrative lockingdevice. The locking device is generally shown at 400, and includes abody member 401 having an attachment mechanism 402 at one end and asecuring mechanism 404 at the other. The attachment mechanism 402includes a first hook member 406 and a second hook member 408. The firsthook member 406 and the second hook member 408 are adapted to extendaround a substantial portion of the shaft of an endoscope or the like.Thus, the first hook member 406 and the second hook member 408 may clipthe body member 401 to the desired shaft.

The securing mechanism 404 includes a J-shaped guidewire opening 410 anda flap-type catheter opening 412. The J-shaped guidewire opening 410operates similar to that described above. The flap-type catheter opening412 has a flap 414 formed by cutting the catheter opening 412 from thebody member 401. The flap 414 is preferably curved to form a channel416, wherein the end portion 418 of the channel 416 loops back to nearthe surface of the body member 401. In this configuration, a catheter orguidewire may be selectively provided in the channel 416, which may bendthe flap away from the body member 401. Accordingly, the flap 412 mayprovide force between the guidewire or catheter and the body member 401to effectively secure the guidewire or catheter to the body member 401.

FIG. 15 is a partial side view of yet another illustrative lockingdevice 500. The locking device 500 is positioned between the side port504 and the main shaft 506 of the endoscope 502. The locking deviceincludes a body member 510 that is attached to the main shaft 506 usinga strap 512. Preferably, the strap 512 extends around the entirecircumference of the main shaft 506. Further, the body member 510 mayinclude a guidewire opening 514 and one or more catheter openings 516,as shown.

Refer now to FIG. 16, which illustrates a side view of a single operatorexchange catheter assembly 800 in accordance with another embodiment ofthe present invention. Except as specifically described herein, catheterassembly 800 is the same in form and function as catheter assembly 30described previously. Catheter assembly 800 includes a standard hubassembly 802 connected to the proximal end of an elongate shaft 804.Elongate shaft 804 includes a proximal portion 806 and a distal portion808. Preferably, the proximal shaft portion 806 comprises a multi-lumenextrusion such as bi-lumen or tri-lumen tubing. Also preferably, thedistal shaft portion 808 comprises a single lumen extrusion. Across-sectional view of the proximal portion 806 of the elongate shaft804 is illustrated in FIG. 17. Similarly, a cross-sectional view of thedistal portion 808 of the elongate shaft 804 is illustrated in FIG. 18.The various embodiments of the junction between the proximal shaftportion 806 and the distal portion 808 are discussed in more detail withreference to FIGS. 19A–19C. In addition, the various distal tip 818embodiments of the distal shaft portion 808 are discussed in more detailwith reference to FIGS. 23A–23C. Common features of each embodiment arediscussed in detail with reference to FIGS. 16, 17, and 18.

Catheter assembly 800 includes a distal guidewire port 810 disposed atthe distal end of the distal shaft portion 808. A proximal guidewireport 812 is disposed adjacent the proximal end of the distal shaftportion 808. The proximal guidewire port 812 may be disposed along anyportion of the shaft 804 distal of the hub assembly 802 and proximal ofthe distal guidewire port 810. Preferably, the proximal guidewire port812 is disposed closer to the distal end of the elongate shaft 804 tominimize the required length of the guidewire (not shown) for usetherewith.

Catheter assembly 800 also includes a channel 814 providing access tothe guidewire lumen 820 from the exterior of the catheter shaft 804. Thechannel 814, which may be shaped as described with reference to FIGS. 1Dand 1E, extends from the proximal guidewire port 812 to a proximalchannel end 816. The channel 814 may have any suitable length and mayeven be omitted while maintaining single operator exchange capabilities.

With reference to FIG. 17, the proximal shaft portion 806 includes aguidewire lumen 820 and an ancillary lumen 822. Although a singleancillary lumen 822 is illustrated, any number of ancillary lumens maybe utilized to suit the particular clinical application. With referenceto FIG. 18, the distal shaft portion 808 includes a common guidewire andancillary lumen 824. The common lumen 824 accommodates the guidewire(not shown) extending through the distal portion 808 of the elongateshaft 804 and also accommodates the passage of fluid from the ancillarylumen 822 of the proximal shaft portion 806. Accordingly, the commonlumen 824 is in communication with both the guidewire lumen 820 and theancillary lumen 822.

By providing a common lumen 824 to accommodate the guidewire and thepassage of fluid from the ancillary lumen 822, the distal shaft portion808 may have a reduced profile for accessing tortuous and/or smalldiameter duct pathways. Specifically, because separate guidewire andancillary lumens are eliminated in favor of common lumen 824, aseparation layer is not necessary. Eliminating the need for a separationlayer proportionately reduces the profile of the distal shaft portion808.

In order to eliminate the egress of fluid from the common lumen 824 outthe proximal guidewire port 812, it is preferable to provide a seal 830adjacent the proximal guidewire port 812. Preferably, the seal 830provides a fluid seal with or without the guidewire disposed therein.The seal 830 may be located at the junction between the distal end ofthe proximal shaft portion 806 and the proximal end of the distal shaftportion 808.

Alternatively, the seal 830 may be located distal of the proximalguidewire port 812 such that a short length of the guidewire isconstrained in the guidewire lumen proximal of the seal 830.Constraining the guidewire proximal of the seal 830 may be beneficial ifa floppy guidewire is used and/or the guidewire encounters friction atthe seal 830. Constraining the guidewire reduces the potential for theguidewire to buckle as it is being inserted into the seal 830. Theguidewire may also be constrained by providing a separate tube extendinga short distance proximally from the proximal guidewire port 812.

Generally, the seal 830 may be an active-type seal or a passive-typeseal. An active-type seal requires activation by the user such as bypressure or the transmission of force. For example, an active-type sealmay comprise an inflatable balloon which, upon inflation, seals theproximal guidewire exit port. A passive-type seal, by contrast, does notnecessarily require activation by the user.

Passive-type seals include, but are not limited to, gap-type seals andinterference-type seals. Gap-type seals provide a gap that is sizedsufficiently small to inhibit the egress of fluid. For sealing about aguidewire, gap-type seals are sized to provide a gap between the sealand the guidewire, wherein the gap is sized sufficiently small toinhibit the egress of fluid, but is sufficiently large to allow theguidewire to freely move. For example, a gap-type seal may be providedby a tube having an inside diameter slightly larger than the outsidediameter of the guidewire.

Interference-type seals, by contrast, provide contact between surfacesto inhibit the egress of fluid. For example, for sealing about aguidewire, an interference-type seal may be provided by an elastic tubehaving an inside diameter slightly smaller than the outside diameter ofthe guidewire, wherein the elastic tube dilates in response to theguidewire passing therethrough. The inside diameter of the elastic tubepreferably includes a lubricious surface or coating to allow theguidewire to move freely.

An additional example of an interference-type seal comprises a flattenedpolymer tube or opposing polymer flaps in the shape of a duckbill. Theduckbill-type seal may form a seal with or without a guidewire disposedtherein. If used to seal about a guidewire, the flaps readily deflect toallow free movement of the guidewire.

As compared to other types of seals, a duckbill-type seal has theadvantage of providing an effective fluid seal with or without theguidewire disposed therein. In addition, a duckbill-type valve providesa one-way valve, wherein fluid may move in one direction (e.g., a distaldirection), but is prohibited from moving in the other direction (e.g.,a proximal direction toward the guidewire port 812). Although virtuallyany type of seal may be utilized, for purposes of clarity andillustration, a duckbill-type one-way valve 830 capable of sealing abouta guidewire is discussed herein.

Refer now to FIG. 19A, which illustrates a detailed side view of a firstembodiment of the junction between the proximal shaft portion 806 andthe distal shaft portion 808. FIGS. 20A–22A are cross-sectional viewstaken along lines 20A—20A, 21A—21A and 22A—22A, respectively, in FIG.19A. As best seen in 20A, a seal 830 is disposed adjacent the proximalguidewire port 812. The seal 830, in this exemplary embodiment, is aduckbill-type one-way valve. However, the seal 830 may comprise any ofthe types discussed previously.

Duckbill-type valve 830 may comprise an elastomeric tube 831 mounted toa rigid tube 832 disposed in the guidewire lumen at the juncture betweenthe proximal shaft portion 806 and the distal shaft portion 808. Theelastic tube 831 may have a flattened distal portion or may comprise atubular structure having opposing flaps formed in the distal end thereofby cutting two opposing slits through the wall of the tubular structure.Rigid tube 832 may comprise a stainless steel hypotube or other similarmaterial having an inside diameter suitable to accommodate a guidewiretherein. Elastic tube 831 may comprise an elastomer or any suitableelastic material. Both the elastic tube 831 and the rigid tube 832 mayhave a lubricious coating therein to reduce guidewire friction.Preferably, the duckbill-type valve 830 forms a fluid-type sealregardless of whether the guidewire is disposed therein. For purposes ofillustration, seal 830 is shown with the flaps of the elastic tube 831in the open position as they would appear with a guidewire (not shown)disposed therein. Without the guidewire disposed therein, of course, theflaps would be closed to form a fluid tight seal.

The distal end of the proximal shaft portion 806 may be necked down andinserted into an expanded proximal end of the distal shaft portion 808.The ends of the proximal shaft portion 806 and the distal shaft portion808 may be secured by utilizing a suitable adhesive or by thermalbonding. Alternatively, the proximal end of the distal shaft portion 808may be connected to the distal end of the proximal shaft portion 806 byutilizing a metal ring that is swaged or crimped onto the expandedproximal end of the distal shaft portion 808. If the proximal shaftportion 806 and the distal shaft portion 808 are bonded using thermalmeans, a tie layer may be utilized to the extent that the shaft portionscomprise different materials having different adhesion characteristics.

Refer now to FIG. 19B, which illustrates a detailed side view of asecond embodiment of the junction between the proximal shaft portion 806and the distal shaft portion 808. Except as described herein, theembodiment illustrated in 19B is the same in form and function as theembodiment illustrated in FIG. 19A. FIGS. 20B–22B are cross-sectionalviews taken along lines 20B—20B, 21B—21B and 22B—22B, respectively, inFIG. 19B.

As best seen in FIG. 20B, a hood 840 is provided adjacent the proximalguidewire port 812 to facilitate easy insertion of the guidewire. Hood840 includes an enlarged proximal portion 842, preferably having an ovalshape, wherein the minor diameter is approximately equal to the diameterof the proximal shaft portion 806 and the major diameter issubstantially larger than the proximal shaft portion 806. The proximalportion 842 defines an entrance 846 that has a diameter substantiallylarger than the diameter of the proximal guidewire port 812, and intowhich the guidewire may be easily inserted. The proximal end of thedistal shaft portion 808 may include a flared portion 844 to provide asmooth transition from the hood 840.

Refer now to 19C, which illustrates a detailed side view of a thirdembodiment of the junction between the proximal shaft portion 806 andthe distal shaft portion 808. Except as described herein, the embodimentillustrated in FIG. 19C is the same in form and function as theembodiment illustrated in FIG. 19A. In addition, although notillustrated, the hood 840 discussed with reference to FIG. 19B may beutilized in the embodiment illustrated in FIG. 19C. FIGS. 20C–22C arecross-sectional views taken along lines 20C—20C, 21C—21C and 22C—22C,respectively, in FIG. 19C.

As best illustrated in FIG. 20C, this embodiment differs from theembodiments described previously in that the distal shaft portion 808 isinserted into a cored-out portion of the proximal shaft portion 806.Specifically, the distal end of the proximal shaft portion 806 is coredor hollowed to define a circular interior with a single wall exterior.The proximal end of the distal shaft portion 808 is inserted into thecored distal end of the proximal shaft portion 806 and secured theretoby suitable means such as adhesive or thermal bonding.

To facilitate a smooth transition from the proximal shaft portion 806 tothe distal shaft portion 808, a hood 850 is provided at the proximal endof the distal shaft portion 808. Hood 850 includes a flared proximalportion 852 and a distal portion 854 inserted into the common lumen 824of the distal shaft portion 808. The flared portion 852 of the hood 850facilitates the smooth insertion of the guidewire from the seal 830 intothe common lumen 824.

Refer now to FIGS. 23A–23C, which illustrate side views of severalembodiments of the distal tip 818 of the distal shaft portion 808. FIGS.24A–24C illustrate cross-sectional views taken along lines 24A—24A,24B—24B and 24C—24C in FIGS. 23A–23C, respectively. The distal tip 818may have a blunt-tapered tip 818A as illustrated in FIG. 23A, agradually-tapered tip 818B as illustrated in FIG. 23B or a ball-shapedtip 818C as illustrated in FIG. 23C. Although illustrated as having alinear shape, the distal shaft portion 808 and the distal tip 818 mayhave a curve or other contour to facilitate navigation and steering ofthe distal end of the catheter 800. The desired shape of the tip 818 maybe selected based on the particular clinical application and theparticular duct pathway being navigated. The tip shapes illustrated inFIGS. 23A–23C are merely exemplary as many different shapes and sizesmay be employed.

In each of the embodiments, a radiopaque marker band 860 may be disposedin the distal tip 818, preferably inside the tip 818 so as to not affectthe profile or shape of the tip 818. The radiopaque marker band 860facilitates fluoroscopic visualization of the distal end of the catheter800. Although not illustrated, the distal shaft portion 808 and thedistal tip 818 may also include a series of stripes having predeterminedlength, color, and position to facilitate exact longitudinal positioningof the catheter 800 relative to the endoscope (not shown).

In use, the catheter 800 may be used in substantially the same way ascatheter 30 described previously. The primary difference, of course, isthat catheter 800 utilizes a common distal lumen for the guidewire andthe delivery of fluids from the ancillary lumen. Although the use of acommon distal lumen may require the use of a seal at the proximalguidewire port as described herein, the catheter 800 operates andperforms substantially the same as catheter 30. The primary differencein performance relates to the distal shaft portion 808. Specifically,the distal shaft portion 808 has a lower profile. Further, the singlelumen design allows the distal shaft portion 808 and the distal tip 818to be formed in a wide variety of shapes, curves, and sizes.

Refer now to FIG. 25, which illustrates a plan view of a single operatorexchange catheter assembly 900 in accordance with another embodiment ofthe present invention. Catheter assembly 900 includes a standard hubassembly 902 connected to the proximal end of an elongate shaft 904.Elongate shaft 904 includes a proximal portion 906 and a distal portion908. Proximal shaft portion 906 includes a plurality of walls 924defining a guidewire lumen 920 (not shown) and at least one ancillarylumen 922 (not shown). Distal shaft portion 908 includes a wall 926defining a distal lumen 928. Distal lumen 928 terminates at its distalend with a distal guidewire port 910.

Catheter assembly 900 also includes a channel 914 defined by wall 924 ofproximal shaft portion 906. Channel 914 includes a proximal end 916 anda distal end 918. In the embodiment of FIG. 25, channel 914 providesaccess to guidewire lumen 920 from the exterior of proximal shaftportion 906. Walls 924 of proximal shaft portion 906 define a proximalguidewire port 912 (not shown). A guidewire may enter guidewire lumen920 of proximal shaft portion 906 by passing through guidewire port 912.

A flare 930 is also disposed proximate distal end 918 of channel 914. Aremovable hood assembly 940 is disposed about proximal shaft 906proximate channel 914. Flare 930 and removable hood assembly 940 mayeach aid in directing a guidewire toward proximal guidewire port 912.The portion of catheter assembly 900 in which flare 930 and removablehood assembly 940 are disposed may be generally referred to as an entryregion 950. Various embodiments of entry region 950 of catheter assembly900 are discussed in more detail below.

Refer now to FIG. 26, which is a detailed plan view of entry region 950of one embodiment of catheter assembly 900. In the embodiment of FIG.26, flare 930 includes an enlarged portion 932 formed from a portion ofwall 924 of proximal shaft portion 906. One method which may be utilizedto form flare 930 is to apply heat to wall 924 proximate distal end 918of channel 914. When wall 924 has reached a desired temperature, flare930 may be formed using a mandrel, pliers, or other tools. Enlargedportion 932 of flare 930 defines a flare entry port 934 adapted to guidea guidewire toward proximal guidewire port 912 (not shown).

In FIG. 26, removable hood assembly 940 is disposed about proximal shaftportion 906, proximally of flare 930. Removable hood assembly 940 iscomprised of a generally tubular body portion 946, an enlarged portion942, a tab portion 948, and a preferential tear line 952. Enlargedportion 942 of removable hood assembly 940 defines a hood entry port944.

In the embodiment of FIG. 26, preferential tear line 952 is comprised ofa plurality of perforations 954. Other embodiments of perforations 954are possible without deviating from the spirit and scope of the presentinvention. For example, perforations 954 may comprise holes, slots,slits, or dimples. Likewise, other embodiments of preferential tear line952 are possible without deviating from the spirit and scope of thepresent invention. For example, preferential tear line 952 may comprisea groove, or a fold.

Embodiments of the present invention have been envisioned in whichremovable hood assembly 940 does not include preferential tear line 952,and embodiments have been envisioned in which removable hood assembly940 includes a plurality of preferential tear lines 952. In one methodin accordance with the present invention, removable hood assembly 940 isremoved from proximal shaft portion 906 by grasping tab portion 948 andapplying a pulling force which causes body portion 946 of removable hoodassembly 940 to tear along preferential tear line 952. In this manner,removable hood assembly 940 may be selectively removed from proximalshaft portion 906.

FIG. 27 is a partial perspective view of a preferred detachable hooddesign for the catheter 900 of FIG. 25 and entry region 950 of FIG. 26.A guidewire 901 is shown inserted into entrance 951 of hood 940. In use,the guidewire 901 will extend into the guidewire lumen 920 of FIG. 28through the proximal guidewire port 912, also shown in FIG. 28. FIG. 27particularly illustrates how the preferred shape of hood 940 aids inguidewire insertion into the common guidewire and ancillary lumen 928.Hood entrance 951 gradually reduces in diameter from enlarged proximalportion 905 into the opening of proximal guidewire port 912. As theguidewire 901 is inserted into the hood, the gradually reducing diameterforces the guidewire 901 into the opening of the proximal guidewire port912. The guidewire 901 may then be further fed through the valve or seal960 disposed distal of the proximal guidewire port 912, entering thecommon guidewire and ancillary lumen 928. As also depicted in FIG. 27,the proximalmost shape 905 of the hood generally matches the lumen 903within which the hood is disposed. This prevents a guidewire frompassing by the hood when inserted into lumen 903.

Refer now to FIG. 28 which is a cross-sectional view of entry region 950of catheter assembly 900. In FIG. 28, it may be appreciated that hoodentry port 944 of removable hood assembly 940 is in fluid communicationwith channel 914 of proximal shaft portion 906. When the end of aguidewire is inserted into hood entry port 944, removable hood assembly940 guides the guidewire into channel 914 of proximal shaft portion 906.If the guidewire is urged further in a distal direction it will enterguidewire lumen 920 via proximal guidewire port 912. If the guidewire isurged still further in a distal direction, it will pass through a valve960 which is disposed within guidewire lumen 920. If the guidewire isurged still further in a distal direction, it will enter distal lumen928 of distal shaft portion 908.

Valve 960 is comprised of a body portion 962, and a plurality of sealingportions 964. Body portion 962 and sealing portions 964 may be comprisedof the same materials or different materials. In a presently preferredembodiment, body portion 962 and sealing portions 964 are both comprisedof thermoplastic elastomer (TPE).

Refer now to FIG. 29 which is a cross-sectional view of entry region 950of catheter assembly 900. In FIG. 29, catheter assembly 900 has beenpositioned within a lumen 972 defined by a device 970. Device 970 may beany device intended for use with catheter assembly 900. For example,device 970 may be an endoscope, a sheath, a guide catheter, or anintroducer. As shown in FIG. 29, lumen 972 of device 970 has a diameterof F. In a presently preferred embodiment, the outer diameter ofremovable hood assembly 940 is substantially equal to lumen diameter F.

A guidewire may be inserted into lumen 972 of device 972 and urged in adistal direction until it encounters removable hood assembly 940. Asshown in FIG. 29, removable hood assembly 940 is adapted to guide theend a guidewire into channel 914. In a presently preferred embodiment,removable hood assembly 940 extends substantially across lumen 972 ofdevice 970. In this manner, removable hood assembly 940 is adapted toprevent the guidewire from bypassing hood entry port 944.

Refer now to FIG. 30 which is a cross-sectional view of entry region 950of catheter assembly 900. In FIG. 30, removable hood assembly has beenremoved from proximal shaft portion 906 and catheter assembly 900 hasbeen positioned within a lumen 982 defined by a device 980. As in theprevious FIG., device 980 may be any device intended for use withcatheter assembly 900. For example, device 980 may be an endoscope, asheath, a guide catheter, or an introducer. As shown in FIG. 30, lumen982 of device 980 has a diameter of G. In a presently preferredembodiment, the outer diameter of catheter assembly 900 proximate flare930 is substantially equal to lumen diameter G.

A guidewire may be inserted into lumen 982 of device 980 and urgeddistally until it reaches flare 930. When the distal end of a guidewireencounters flare 930, it will pass through flare entry port 934. Asshown in FIG. 30, flare 930 is adapted to guide the end a guidewire intoproximal guidewire port 912. In a presently preferred embodiment, theportion of catheter assembly 900 proximate flare 930 extendssubstantially across lumen 982 of device 980. In this manner, flare 930is adapted to prevent the guidewire from bypassing flare entry port 934.

By referring to FIGS. 29 and 30 simultaneously, it may be appreciatedthat a physician may purchase a single catheter assembly 900, and usethat catheter assembly in conjunction with both device 970 and device980. In fact, a single catheter assembly may be used with a plurality ofdevices. When removable hood assembly 940 is disposed about proximalshaft portion 906 of catheter assembly 900, catheter assembly 900 may beused in conjunction with any device having a lumen with a diametersimilar to diameter F. Removable hood assembly 940 may be selectivelyremoved to adapt catheter assembly 900 for use with any device having alumen with a diameter similar to diameter G. It should be noted that ina presently preferred embodiment, both removable hood assembly 940 andflare 930 are substantially flexible, so that they may be inserted intolumens having various diameters. Embodiments of catheter assembly 900have also been envisioned which include more than one removable hoodassembly 940.

The distal end of proximal shaft portion 906 is disposed within expandedproximal end 956 of distal shaft portion 908. A ring 966 is disposedabout expanded proximal end 956 of distal shaft portion 908. In apresently preferred embodiment, ring 966 is swaged or crimped to fixexpanded proximal end 956 of distal shaft portion 908 to distal end 958of proximal shaft portion 906. Distal end 958 of proximal shaft portion906 may also be fixed to expanded proximal end 956 of distal shaftportion 908 utilizing a suitable adhesive or by thermal bonding.

As described above, when the end of a guidewire is inserted into eitherflare entry port 934 or hood entry port 944, the guidewire will bedirected into channel 914 of proximal shaft portion 906. If theguidewire is urged further in a distal direction it will enter guidewirelumen 920 via-proximal guidewire port 912. If the guidewire is urgedstill further in a distal direction, it will pass through a valve 960which is disposed within guidewire lumen 920. If the guidewire is urgedstill further in a distal direction, it will enter distal lumen 928 ofdistal shaft portion 908.

As best illustrated in FIG. 28, distal lumen 926 of distal shaft portion908 is in fluid communication with guidewire lumen 920 of proximal shaftportion 908. In the embodiment of FIGS. 26–30, the proximal end ofdistal shaft portion 908 is disposed within the distal portion of theproximal shaft portion 906. The distal end of the proximal shaft portion906 is cored or hollowed to define a circular interior with a singlewall exterior. The proximal end of the distal shaft portion 908 has beeninserted into this cored portion of proximal shaft portion 906 andsecured thereto by suitable means such as adhesive or thermal bonding.Those of skill in the art will appreciate that other embodiments ofentry region 950 are possible without deviating from the spirit andscope of the present invention. An additional exemplary embodiment isillustrated in FIG. 31.

Refer now to FIG. 31, which is a detailed plan view of an additionalembodiment of entry region 950 of catheter assembly 900. In theembodiment of FIG. 31, distal shaft portion 908 includes an expandedproximal end 956. A distal end 958 of proximal shaft portion 906 isdisposed within expanded proximal end 956 of distal shaft portion 908. Aring 966 is disposed about expanded proximal end 956 of distal shaftportion 908. In a presently preferred embodiment, ring 966 is swaged orcrimped to fix expanded proximal end 956 of distal shaft portion 908 todistal end 958 of proximal shaft portion 906. Distal end 958 of proximalshaft portion 906 may also be fixed to expanded proximal end 956 ofdistal shaft portion 908 utilizing a suitable adhesive or by thermalbonding.

A flare 930 is disposed on proximal shaft 906. Flare 930 includes anenlarged portion 932 formed from a portion of wall 924 of proximal shaftportion 906. Enlarged portion 932 of flare 930 defines a flare entryport 934. A removable hood assembly 940 is disposed about proximal shaftportion 906, proximally of flare 930.

Removable hood assembly 940 is comprised of a generally tubular bodyportion 946, a enlarged portion 942, and a tab portion 948. Enlargedportion 948 of removable hood assembly 940 defines a hood entry port944. In one method in accordance with the present invention, removablehood assembly 940 is removed from proximal shaft portion 906 by graspingtab portion 948 and applying a pulling force which causes body portion946 of removable hood assembly 940 to tear. In this manner, removablehood assembly 940 may be selectively removed from proximal shaft portion906.

Refer now to FIG. 32 which is a cross-sectional view of entry region 950of catheter assembly 900. In FIG. 32, it may be appreciated that bothflare entry port 934 and hood entry port 944 are in fluid communicationwith channel 914 of proximal shaft portion 906. When the end of aguidewire is inserted into either flare entry port 934 or hood entryport 944, the guidewire will be directed into channel 914 of proximalshaft portion 906. If the guidewire is urged further in a distaldirection it will enter guidewire lumen 920 via proximal guidewire port912. If the guidewire is urged still further in a distal direction, itwill pass through a valve 960 which is disposed within guidewire lumen920. If the guidewire is urged still further in a distal direction, itwill enter distal lumen 928 of distal shaft portion 908.

Those skilled in the art will recognize that the present invention maybe manifested in a wide variety of forms other than the specificembodiments contemplated and described herein. Accordingly, departuresin form and detail may be made without departing from the scope andspirit of the present invention as described in the appended claims.

1. A catheter having a proximal end and a distal end, the cathetercomprising: a proximal portion including a first lumen extendingtherein; a distal portion including a guidewire lumen sized to allowfluid flow therethrough even when a guidewire is disposed therein, theguidewire lumen being in fluid communication with the first lumen; and aport adapted to allow a guidewire disposed outside the proximal portionto enter the guidewire lumen between the proximal portion and the distalportion, the port adapted to allow a guidewire to pass therethrough, theport also adapted to prevent a fluid from passing therethrough.
 2. Acatheter as in claim 1, wherein the proximal portion includes a channelextending for a major portion thereof, the channel sized to allow aguidewire to rest therein.
 3. A catheter as in claim 2, wherein the portis co-axial with the channel.
 4. A catheter as in claim 3, wherein thechannel terminates at the port.
 5. A catheter as in claim 2, wherein thechannel leads into the port.
 6. A catheter as in claim 1, furthercomprising a hood, the hood including an opening extending therethrough,the size of the opening decreasing from a proximal portion of the hoodto a distal portion of the hood, wherein the hood is disposed such thatthe distal portion of the hood is adjacent the port.
 7. A catheter as inclaim 6, wherein the distal portion of the hood leads into the port. 8.A catheter as in claim 6, wherein the hood is removable.
 9. A catheteras in claim 6, wherein the catheter is adapted for insertion through anendoscope, and the hood is sized to correspond to the inner diameter ofa lumen extending through the endoscope.
 10. A catheter as in claim 1,further comprising an opening adjacent the distal end, the guidewirelumen terminating at the opening, wherein a location distally adjacentto the port is in fluid communication with the opening.
 11. A catheteras in claim 1, wherein passage of the guidewire through a lumen in thedistal portion does not increase the number of lumens in the distalportion relative to the number of lumens in the proximal portion.
 12. Acatheter as in claim 1, wherein the proximal portion of the catheteralso defines a second lumen, and wherein the guidewire lumen is in fluidcommunication with the second lumen.
 13. A catheter as in claim 1,wherein the port is adapted to prevent a fluid from passing therethroughwith and without a guidewire passing therethrough.
 14. A catheter havinga proximal end and a distal end, the catheter being a single operatorexchange catheter adapted to receive a guidewire in a distal portionextending between a proximal guidewire port and the distal end, theproximal guidewire port being nearer the distal end than the proximalend, the catheter comprising: directing means for directing a guidewireinto the distal portion, the directing means disposed about thecatheter; and preventing means for preventing fluid flow through theproximal guidewire port.
 15. A catheter as in claim 14, furthercomprising: a first lumen extending from the proximal end to the distalportion; a guidewire lumen adapted for receiving a guidewire from theguidewire port, the guidewire lumen in fluid communication with thefirst lumen.
 16. A catheter as in claim 15, wherein the guidewire lumenis sized to allow fluid flow therethrough even when a guidewire isdisposed therein.
 17. A catheter as in claim 15, further comprising asecond lumen extending from the proximal end to the distal portion,wherein the guidewire lumen is also in fluid communication with thesecond lumen.
 18. A catheter as in claim 14, wherein the catheter isadapted for use as a biliary catheter by passage through a lumen of anendoscope, wherein the directing means is sized to correspond to theendoscope lumen.
 19. A catheter as in claim 18, wherein the directingmeans includes a funnel shaped member, the funnel shaped member having agreater diameter at a proximal end and a lesser diameter at a distalend, the funnel shaped member distal end being disposed adjacent theproximal guidewire port, the funnel shaped member proximal end shaped tocorrespond to the shape of the endoscope lumen.
 20. A catheter having aproximal end and a distal end, the catheter being a single operatorexchange catheter adapted to receive a guidewire in a distal portionextending between a proximal guidewire port and the distal end, thecatheter being adapted for use as a biliary catheter by passage througha lumen of an endoscope, the proximal guidewire port being nearer thedistal end than the proximal end, the catheter comprising: directingmeans for directing a guidewire into the distal portion, the directingmeans including a funnel shaped member, the funnel shaped member havinga greater diameter at a proximal end and a lesser diameter at a distalend, the funnel shaped member distal end being disposed adjacent theproximal guidewire port, the funnel shaped member proximal end shaped tocorrespond to the shape of the endoscope lumen; and preventing means forpreventing fluid flow through the proximal guidewire port; wherein thedirecting means includes a funnel shaped member, the funnel.